A. Field of the Invention
The present invention relates to an inductor, and particularly to a general-purpose inductor operable under various supply voltages.
B. Description of the Related Art
Inductors have been broadly applied to various types of circuits, such as power factor correction circuit, to solve the problem of harmonic in supply voltages.
Regarding the application of working voltage in a circuit, conventional inductors can be roughly classified into two categories, namely general-purpose inductors for variable voltages and special purpose inductors for a predetermined voltage.
As shown in FIG. 1 and FIG. 2, a harmonic inductor includes: two E-like core members 31, two bobbins 32, and a magnetically permeable iron sheet 34. As to the harmonic inductor, though it is operable under various supply voltages, its structure is very complex. Furthermore, two coils are connected in series to form another single coil without any additional performance applicable to other devices. Additionally, since the two coils are connected in series to form a single coil when applied, it is necessary for the two coils to have the same size coil diameter to meet the regulations of harmonic current. That is, based on the consideration of the safety, the suitable size of the coil diameter for the coils have to be relatively larger. Thus, it is impossible to effectively minimize the overall volume of the inductor.
In view of the above, an objective of the invention is to provide an inductor with a simplified structure and a miniature volume that is operable under various supply voltages.
Another objective of the invention is to provide an inductor operable in association with all types of selecting switches and under various supply voltages.
The characteristics of the inductor operable under various supply voltages according to the invention are that two coils with different coil diameters are connected in series and provided on a bobbin so as to minimize the overall volume of the inductor.
Additionally, another characteristics of the inductor operable under various supply voltages according to the invention are to connect the connecting part of the same coils to all types of selecting switches so that the inductor can be operable under various supply voltages.
In order to complete the above objective, the inductor operable under various supply voltages according to the invention includes: a first coil used as a primary connecting coil for supply voltage, a second coil used as a secondary connecting coil for supply voltage, a bobbin for supporting and mounting the first and the second coils, and a core for interacting with the first and the second coils to produce inductance, wherein the coil diameter of the first coil is larger than the coil diameter of the second coil, and the first and the second coils are connected in series, whereby input electric current can flow through one coil selected from the first and second coils by utilizing a selecting switch, so as to generate sufficient corresponding inductance according to various input supply voltages. As a result, the inductor operable under various supply voltages according to the invention, indeed, is operable in association with all types of selecting switches.